It just works.
Its a concept that gets short shrift outside of the Apple world.
It just works? What about antenna-gate and Apple Maps? What about all the things that the iPhone can't even do? What about Flash sites?
And all those arguments are right. I've even made a few of them myself.
But there's something in there which goes beyond the normal concept of a computing device, which is what most Android smartphones are - computing devices that make calls, but computing devices nonetheless.
Apple have built a consumer device, a smart device, that has fairly rigid constraints over what it can and can't do. What it will or won't let you do.
But it just works.
And for me that's what I need right now.
I still have my Android phone (phones, technically, but let's not quibble) but when I want something that just does what I want, when I want it, without making me jump through hoops to do it the iPhone is what fits the bill.
The iPhone 5 is not functionally much different to the 4S, but I don't remember feeling the same compulsion to use the latter. Which suggests that its my needs that have changed rather than the relative benefits of the platforms. It also suggests that at some stage I'll regain the desire to push the limits of what can be achieved with a smartphone and switch platforms again. But for now I'll stick with the iPhone.
After all, it just works.